Unlike the previous goils having octopus-like forms, this one kinda takes on a serpentine figure, naga-esque if you will. My favourite part about her design is the claw sprouting out of her right eye, it's a very grotesque detail to me and I love grotesque. She possesses a deadly stinger at the end of her tail, a drop of Arnus's venom is enough paralyse your entire body.

I think out of all the goils, Arnus is the least large out of all of them in the stomach department. Though it doesn't stop her from being a greedy guts, if anything she's actually got a larger stomach capacity than both Argus and Acauldrus in this form. It could be why she doesn't go down to Underrealm much, cause most of the time she gets extremely big from either her own gluttony or from her relatives.